Articles like this are bullshit. Not in the sense that they're untrue, but in the sense it won't change a thing. Men buy diamonds because women want them. Women want them to show off to other women.
Even if nothing changes as far as diamonds are concerned, it is still worth writing this article - imagine someone landing on this article and he/she hasn't heard of priceonomics before - they will read through their excellent other posts and learn a thing or two.
And lastly, look at the intense discussion at HN on this article. How many articles do that?
This is an awesome blog, consistently writing high quality articles. Thanks for writing this guys.